1. Field of the Invention
The present invention relates to a method of manufacturing a pointing stick; in particular, the invention relates to a method capable of manufacturing a pointing stick with strain gages that are not affected by adhesives.
2. Description of the Related Art
In general, the input and output data processing of a computer are carried out interactively with a user via a data input/output device. For example, the data input device may be a keyboard or a pointing device, while the data output device may be a display screen of a computer that displays such data as characters and graphics. Examples of pointing devices include a pointing stick, a digitizer, a mouse, and a track ball.
In recent years, it has become even more popular to use the pointing device, in addition to the keyboard, as the data input device to apply in fields such as data processing. The reason for the popular use of the pointing device can be attributed to the newfound convenience brought by operating systems and application software that employs a free-to-move pointer in response to interactive operations by a user for which the use of the pointing device is essential. For example, Windows operations and icon operations are examples of the interactive operations.
On the other hand, the computer today is no longer limited to the bulky desktop type having an independent computer body, keyboard, and display monitor. Recently, portable computers such as the laptop type, notebook type and palm-top type have become popular, and such portable computers have an integrated computer body, keyboard, and display. The portable computer such as the laptop type can be conveniently carried because it is light and compact.
However, because of the increasing popularity of using such portable computers as the laptop type, the operating conditions under which the pointing device is incorporated into a computer has become more diversified. In other words, the pointing device of a desktop type computer is typically operated on the top of a desk while the pointing device for the portable computer is more compact-sized and operable away from the desk.
For this reason, it is desirable that the pointing device used with the portable computer does not require a setup area such that the pointing device is integrated with the portable computer. In addition, there is also a demand to reduce the setup area of the pointing device of the desktop computer, where it is more desirable to assemble the pointing device within the computer in order to meet such a demand.
In general, the pointing stick is divided into two groups: a pillared-type and a planar-type. Because the present invention is mainly aimed at the planar-type, the following description is simply about the structure, the assembling manner and the operating theorem of the planar-type pointing stick.
Refer to FIG. 1. FIG. 1 is a perspective view showing an example of a conventional pointing stick. In FIG. 1, a pointing stick 10 comprises a resilient substrate 12, a post 11, a plurality of strain gages 13 and a plurality of electrodes 14.
When an operator places his or her finger tip on the tip end of the post 11 and displaces the tip end in an arbitrary direction, a strain dependent on the strain of the substrate 12 generated by the force applied on the tip end of the post 11 is generated at each strain gage 13. Since the resistance of the strain gage 13 is in proportion to the degree of the strain engaged thereupon, it is possible to determine the moving direction and moving distance of the cursor or pointer on the display screen, based on the changes in the resistance of each of the strain gages 13, by detecting the change in the resistance of each strain gage 13.
In the conventional method of manufacturing a pointing stick, the assembling manner between the post and the substrate is shown in FIG. 2. After adhesives 126 are added on a post 121 or a substrate 122, the post 121 is disposed on a predetermined position of the substrate 122. Then, the post 121 and the substrate 122 are combined to form a pointing stick 120.
The conventional method of manufacturing a pointing stick can still be applied to the pillared-type pointing stick and the planar-type pointing stick because their strain gages are disposed on the post or on the position, far away from the post, of the substrate. However, after the overall size of the pointing stick decreases continuously, the distance between the strain gages, on the post or the substrate, and the boundary between the post and the substrate decreases correspondingly. As a result, the excessive adhesive is easily stained with the strain gages, and the sensitivities of the pointing stick are constrained. Moreover, because the strain gages of the pointing stick as shown in FIG. 1 are disposed on the substrate in a partly overlapped manner, the adhesive will be stained with the strain gages, non-contact with the post, when the adhesive are added in a manner as shown in FIG. 2. Then, the hardened adhesive may influence the operation and the sensitivities of the strain gages.
In view of the disadvantages of the aforementioned conventional method of manufacturing a pointing stick, the present invention provides a method of manufacturing a pointing stick comprising: (a) providing a substrate; (b) providing a post; (c) disposing the post on a predetermined position of the substrate in a manner to form a gap between the substrate and the post; (d) supplying a predetermined amount of adhesives into the gap; and (e) heating the adhesives to combine the post and the substrate.
Accordingly, the present method further comprises: forming a hollow portion and a plurality of protrusions on the substrate in step (a); disposing the post on the substrate in a manner that the post is abutted against the protrusions in step (c); and supplying the adhesives through the hollow portion in step (d)
Furthermore, the present invention provides a method of manufacturing a pointing stick comprising: (a) providing a substrate and a post; (b) disposing the post on the substrate; (c) providing an auxiliary plate; (d) disposing the auxiliary plate on a predetermined position of the substrate in a manner to form a gap between the substrate and the auxiliary plate; (e) supplying a predetermined amount of adhesives to the gap; and (f) heating the adhesives to combine the auxiliary plate and the substrate.